UrzaGatherer is a complete and convenient tool to handle your Magic The Gathering cards collection.
You can also use it as the perfect companion to build and evaluate your decks or to track your life counters.
Statistics for your collection and your decks are also available.

Detailled feature lists:

All Magic the Gathering cards in a single database

Create, test and analyse your decks

Import and export your decks to various formats (.csv, .txt, etc.)

Customize your wallpaper or your lockscreen

Evaluate your collection

Use the life counters tool to track your life and poison counters during a game